HowStuffWorks "Traffic Light Information"

Page

How does a traffic light detect that a car has pulled up and is waiting for the light to change?

Lots More Information

More To Explore

More Great Links

Top 10 Green Driving Tips

5 Scariest Stunt Car Feats

The Ultimate CarStuff Fan Quiz

5 Warning Signs You Need New Tires

10 Most Expensive Classic Cars

Watch American Chopper videos >>

Have new technologies made cars less safe?

Today, the average new car has between 30 and 80 electronic control systems under the hood. With technology-based recalls making headlines, it's easy to wonder: Is all this technology making cars more dangerous?

Why is it still necessary to crash test vehicles?

There's always going to be some risk involved with automobile travel. Crash testing helps remove some of that risk. However, given the availability of modern computer modeling, is it still necessary to destroy actual vehicles?